The Test Request <1> message forces a heartbeat from the opposing application. The Test Request <1> checks sequence numbers and verifies line status. The opposite application responds to the Test <1> with a Heartbeat <0> containing the TestReqID <112>.

TagField NameRequiredComments
Standard HeaderYesMsgType <35> = 1
112TestReqIDYesIdentifier included in Test Request <1> message to be returned in resulting Heartbeat <0>
Standard trailerYes